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Davuluri, R.

Publications and source records attributed to Davuluri, R..

2 recordsLinked to original sources

DNABERT: pre-trained Bidirectional Encoder Representations from Transformers model for DNA-language in genome

Deciphering the language of non-coding DNA is one of the fundamental problems in genome research. Gene regulatory code is highly complex due to the existence of polysemy and distant semantic relationship, which previous informatics methods often fail to capture especially in data-scarce scenarios. To address this challenge, we developed a novel pre-trained bidirectional encoder representation, named DNABERT, that forms global and transferrable understanding of genomic DNA sequences based on up and downstream nucleotide contexts. We show that the single pre-trained transformers model can simultaneously achieve state-of-the-art performance on many sequence predictions tasks, after easy fine-tuning using small task-specific data. Further, DNABERT enables direct visualization of nucleotide-level importance and semantic relationship within input sequences for better interpretability and accurate identification of conserved sequence motifs and functional genetic variants. Finally, we demonstrate that pre-trained DNABERT with human genome can even be readily applied to other organisms with exceptional performance.

bioinformatics

Frizzled-7 Identifies Platinum Tolerant Ovarian Cancer Cells Susceptible to Ferroptosis

Defining traits of platinum tolerant cancer cells could expose new treatment vulnerabilities. Here, new markers associated with platinum tolerant cells and tumors were identified by using in vitro and in vivo ovarian cancer (OC) models treated repetitively with carboplatin and validated in human specimens. Platinum-tolerant cells and tumors were found to be enriched in ALDH (+) cells, formed more spheroids, and expressed increased levels of stemness-related transcription factors compared to parental cells. Additionally, platinum-tolerant cells and tumors highly expressed the Wnt receptor, Frizzled 7 (FZD7). FZD7 knock down improved sensitivity to platinum, decreased spheroid formation, and delayed tumor initiation. The molecular signature distinguishing FZD7(+) from FZD7(-) cells included epithelial-to-mesenchymal (EMT), stemness, and oxidative phosphorylation enriched gene sets. Overexpression of FZD7 activated the oncogenic factor Tp63, driving upregulation of glutathione metabolism pathways, including glutathione peroxidase 4 (GPX4), which protects cells from chemotherapy-induced oxidative stress. FZD7(+) platinum-tolerant OC cells were more sensitive and underwent ferroptosis after treatment with GPX4 inhibitors. FZD7, Tp63 and glutathione metabolism gene sets were strongly correlated in the OC Tumor Cancer Genome Atlas (TCGA) database and in human OC specimens residual after chemotherapy. These results support the existence of a platinum-tolerant cell population with partial stem cell features, characterized by FZD7 expression and dependent on FZD7-{beta}-catenin-Tp63-GPX4 pathway for survival. The findings reveal a novel therapeutic vulnerability of platinum tolerant cancer cells and provide new insight into a potential "persister cancer cell" phenotype.

cancer biology